Impairments baseband model in-phase and quadrature-phase Imbalance (IQI) and Residual hardware impairments (RHI) are two key factors degrading the performance of wireless communication systems (WCSs), particularly when high-frequency bands are employed, as in 5G systems and beyond. The impact of either IQI or RHI on the performance of various WCSs has been investigated exclusively in a separate way. To fill this gap, in this paper, the joint effect of both IQI and RHI on the performance of a WCS subject to Hyper Fox’s H-fading (HFHF) channel, is investigated. Such a fading model generalizes most, if not all, of well-known fading and turbulence models. To this end, closed-form expressions for the outage probability (OP), Average channel capacity (ACC) under constant power with optimum rate adaptation (ORA) policy, and average symbol error probability (ASEP) for both coherent and non-coherent modulation schemes are derived. Specifically, all the analytical expressions are derived for three different scenarios: (i) ideal Tx and Rx impaired, (ii) Tx impaired and ideal Rx, and (iii) both Tx and Rx are impaired. Further, asymptotic expressions for OP, ACC under ORA policy, and ASEP are obtained, based on which, insightful discussions on the IQI and RHI impacts are made.$\alpha -\mu $and Málaga$\mathcal {M}$turbulence with pointing error distribution models have been considered as particular cases of the HFHF distribution. The analytical derivations, endorsed by simulation results, demonstrate that the RF impairments’ effects should be seriously taken into account in the design of next-generation wireless technologies.

In this paper, the upper bound and asymptotical approximation for the bit error rate (BER) as well as for the frame error rate of linear block codes under maximum-likelihood decoding operating over exponentially correlated (EC) generalized-fading channels are proposed. Particularly, our analysis takes the convolutional codes as an example and three different fading scenarios are considered, namely Rice, Nakagami-m, and Weibull fading. Such scenarios have a common property that is spherically invariant random process (SIRP). Our analysis relies on the derivation of new lower bounds per each eigenvalue since the BER as well as the FER expressions are written in terms of the pairwise error probability, which by its turn depends on the eigenvalues of the channel covariance matrix. Based on that, the upper bounds and asymptotic expressions of the considered metrics subject to the three above fading models are derived, which show to be tighter than the previous results published elsewhere in the literature, especially for the high signal-to-noise ratio regions.

In this paper, a tighter upper bound for the bit error rate (BER) of convolutional codes operating under exponentially correlated Nakagami- m fading is proposed. Our analysis relies on the derivation of new lower bounds per each eigenvalue since the BER expression is written in terms of the pairwise error probability, which by its turn depends on the eigenvalues of the channel covariance matrix. In comparison to previous results published elsewhere in the literature, the proposed bounds are shown to be tighter, specially for high signal-to-noise ratio regions, being therefore of great importance and usefulness for the forthcoming researches in the field. Moreover, this result can be generalized to all linear block codes as well as other fading models as the proposed eigenvalues' upperbounds are the main key of this work.

This paper presents tighter bounds on the pairwise error-event probability and therefore very tighter upper bounds of bit error rate(BER) for communication systems employing convolutional code over Rayleigh fading channel with exponential correlation coefficient. To obtain our bound, we start by proposing a closed form upper bound for Gaussian Q-function and as well as deriving a new lower bound of each channel covariance matrix eigenvalue. The simulation results show that our proposed bound is tighter than those previously developed, especially when the covariance parameter q increases. A gain of over 6.5dB was achieved for q = 0.95 at BER=10-5from the better previous bound, whereas for the lower values of q we reach the simulated curve.